Biological samples, such as body fluids, are often collected for testing and/or analysis. Testing and/or analysis of the biological samples may assist in diagnosis of many ailments. Often, the biological sample may be collected in a sample collection device, stored, and transported in the sample collection device for further analysis. The sample collection device may include certain chemical reagent/s to stabilize, pre-process, and/or to process the collected biological sample during storage in the sample collection device. The chemical agents may be present in form of granules, capsules, loose powder, liquid, or tablets inside the sample collection device.
In one example, a mucolytic agent, such as N-acetyl-L-cysteine (NALC) in a tablet form may be present inside a sample collection device. When a biological sample, such as sputum, may come in contact with NALC inside the sample collection device, NALC may reduce viscosity of the biological sample, making the biological sample suitable for further analysis.
However, the inventors herein have recognized problems with the above-mentioned approach, including constituents of the NALC tablet not solubilizing completely, and certain constituents in the NALC tablet interfering with molecular reactions such as antibody-based analysis of the biological sample, and/or DNA detection in the biological sample by polymerase chain reaction (PCR). Additionally, the tablet may include constituents, which may alter microbial survivability either by being a food source or by being toxic to certain types of microbes present in the biological sample, thereby interfering with accurate analysis of the biological sample.
The inventors herein propose a composition for a mucolytic tablet for a sample collection device, including 15% to 65% by weight of N-acetyl L-cysteine (NALC), 6% to 30% by weight of a buffering agent, 10% to 14% by weight of a water soluble anti-adherent, and 2% to 10% by weight of at least one chelating and lubricant agent, wherein the mucolytic tablet solubilizes in a resuspension buffer. The resuspension buffer may include between 60 mM to 67 mM phosphates, and 56-60 mM sodium citrate. In one example, the phosphates of the resuspension buffer may be from 30-36 mM disodium hydrogen phosphate and 30-36 mM dipotassium hydrogen phosphate. A weight of the mucolytic tablet may range between 0.045-0.055 grams and a time for dissolving the mucolytic tablet in 3-6 ml of the resuspension buffer may be between 1.00-1.3 minutes. NALC in 3-6 ml of resuspension buffer with the dissolved mucolytic tablet may be between 4-6 mg/ml and a pH of the resuspension buffer with the dissolved mucolytic tablet may be between 6.2-6.5.
An example method for preparing a mucolytic tablet may include premixing constituents of a mucolytic tablet, followed by desiccating the premixed constituents, the premixed constituents including 15% to 65% by weight of N-acetyl L-cysteine (NALC), 6% to 30% by weight of a buffering agent, 10% to 14% by weight of a water-soluble anti-adherent, 2% to 10% by weight of at least one chelating and lubricating agent, and preparing the mucolytic tablets from the desiccated premixed constituents. Desiccating the premixed constituents may include desiccating under vacuum between 26° C. to 28° C. for 20 hours-2 weeks. Preparing the mucolytic tablet may include use of a tablet-punching machine at a speed between 25.5-40.5 g/second with a compression force between 3.5-4.5 pascal.
In one example, a sample collection device may include a container with a closure assembly, a reagent chamber inside the container, the reagent chamber fluidically connected to an inner volume of the container, and a mucolytic tablet in the reagent chamber, wherein a composition of the mucolytic tablet may include 15% to 65% by weight of N-acetyl L-cysteine (NALC), 6% to 30% by weight of K2HPO4, 10% to 14% by weight of L-Leucine, 2% to 10% by weight of polyethylene glycol, and 0% to 60% by weight of trisodium citrate.
In this way, a mucolytic tablet, including a mucolytic agent NALC, may be dissolved in a resuspension buffer. Upon mixing of the resuspension buffer with a sample collected in a sample collection device, the NALC of the mucolytic tablet may act to reduce the viscosity of the sample. Reduction in viscosity of the sample may make the sample conducive for mixing with additional reagents for forming a homogeneous solution during subsequent analysis for accurate diagnosis of various disease conditions. The formulation of the mucolytic tablet and the composition of the resuspension buffer are configured such that there is no interference with molecular assays and microbial survivability.